It is said that some scientists once suspected that the apocalyptic catastrophe was related to the supernova explosion. Yun Meng put away his thoughts and said.

She saw that Hua Feng on the side had just made a breakfast, a nutritious breakfast as usual. Although eating was no longer particularly necessary to insist on during their period, Hua Feng didn't seem to want to give up eating because of this.

On January 14, 2016, an international team of researchers led by Dong Subo, a researcher at Peking University in China, announced that they had observed the strongest supernova explosion ever recorded in human history, about 200 times more intense than a typical supernova and more than twice as strong as the previous record holder.

But every supernova explosion has not attracted the attention of scientists, and most of them are only regarded as far away, just treated as a general celestial phenomenon. Hua Feng set up Yun Meng's tableware and said while beckoning Yun Meng over.

It is customary for the International Astronomical Union to name a supernova when it receives a report of a supernova discovery. Names are made up of the year of discovery and one or two Latin letters: the first 26 supernovae discovered in a year are named with capital letters from A to Z, such as Supernova 1987A, which was the first supernova discovered in 1987, and those after 26 are named with two lowercase letters, starting with aa, ab, ac, and so on.

Professional and amateur astronomers discover hundreds of supernovae each year (367 in 2005, 551 in 2006 and 572 in 2007), for example the last supernova discovered in 2005 was SN 2005

c, indicating that it was the 367th supernova discovered in 2005.

Historical supernovae are named only by the year they were discovered, such as SN 185, SN 1006, SN 1054, SN 1572 (Tycho supernova) and SN 1604 (Kepler supernova). Alphabetic naming began in 1885, even though only one supernova was discovered in that year (such as SN 1885A and 1907A). The prefix SN, which denotes a supernova, can sometimes be omitted.

There are 4 major observatories whose discoveries do not need to be reported to the International Astronomical Union, namely Nea

by Supe

ova Facto

y，Catali

a Real-Time T

a

sie

t Su

vey，ROTSE collabo

atio

，Paloma

T

a

sie

t Facto

y。 These four observatories have their own supernovae naming rules, and sometimes some discoveries will be named conventionally, or they will be represented by the coordinates of a supernova, or some supernovae will not be named.

Such as the world-famous Paloma Hill Observatory of Paloma

T

a

sie

t Facto

The supernovae discovered by y all start with PTF, and the first amateur supernova in the mainland, discovered by Sun Guoyou, a Chinese astronomy enthusiast, and Gao Xing, received the number PTF10acbu given by the Palomar Mountain Observatory.

Ia supernovae lack hydrogen and helium, and the peak of the spectrum is most pronounced with light at a wavelength of 615.0 nanometers of free silicon.

Ib supernova has no free helium atom (He I) of 587.6 nm, and no strong silicon absorption line of 615 nm.

IC supernovae have no or weak helium lines, and no strong silicon 615 nm absorption lines.

Type II Supernovae:

II-P supernovae have a "plateau" on the photometric curve.

II-L supernovae The photometric curve (the change of magnitude versus time, or the exponential change of luminosity versus time) decays "linearly".

If a supernova does not contain hydrogen absorption lines in its spectrum, it is classified as type I, otherwise it is type II. A type can be subdivided according to the absorption lines of other elements. Astronomers believe that these observational differences represent different sources of these supernovae. They are full of the theory of the origin of type II, but although there are some opinions in astronomy explaining the method of occurrence of type I supernovae, these opinions are less certain.

Supernovae of type Ia do not have helium, but they do have silicon. They all originate from the eruption of a white dwarf star that reaches or approaches the Chandrasekhar limit. One possibility is that the white dwarf is in a close binary system, absorbing material from its giant companion until its mass reaches the Chandrasekhar limit.

At that time, the electron degeneracy pressure was no longer enough to offset the gravitational pull of the star itself, and the collapse process could fuse the remaining carbon and oxygen atoms. In the end, the shock wave generated by the fusion reaction blew the star to pieces, which is very similar to the mechanism of nova generation, except that the white dwarf corresponding to the nova does not reach the Chandrasekhar limit, and the carbon and oxygen nuclear reaction does not occur, and the energy generated by the explosion comes from the fusion reaction of hydrogen or helium accumulated on its surface.

The sudden increase in brightness is provided by the energy released during the burst, after which the brightness does not disappear immediately, but slowly decreases over a long period of time, due to the energy released by the decay of radioactive cobalt into iron.

Ib supernovae have helium absorption lines, while Ic supernovae do not have helium and silicon absorption lines, and astronomers are still not clear about the mechanism by which they arise. It is believed that these stars are ending their lives (e.g., type II), but they may have lost hydrogen (and helium in the case of Ic) before (the giant stage), so they do not have hydrogen absorption lines in their spectrum. Ib supernovae may be the result of the collapse of a Wolf-Laleaf star.

If a star is massive, its own gravitational pull can fuse silicon into iron. Because the specific binding energy of iron atoms is already the highest among all elements, fusing iron will not release energy, but will consume the energy instead. When the mass of the iron core reaches the Chandrasekhar limit, it instantly decays into neutrons and collapses, releasing a large number of energy-carrying neutrinos.

Neutrinos transfer part of the energy of the burst to the outer layers of the star. When the shock wave generated by the collapse of the iron core reaches the star's surface a few hours later, the brightness increases, which is called a type II supernova explosion. Depending on the mass of the core, it can become a neutron star or a black hole.

There are also some small variants of type II supernovae, such as type II-P and type II-L, but these only describe the differences in the photometric plot (the plot of II-P has a temporary flat area, while the II-L does not), and the basic principles of the explosion do not differ much.

There is also a theoretical explosion phenomenon known as "supernovae". Supernovae are the cores of extremely massive stars that collapse into black holes and produce two jets of extremely energetic near-light speed, emitting intense gamma rays. This may be the cause of gamma-ray bursts.

Type I supernovae are generally brighter than type II supernovae.

There are several pathways for the formation of supernovae in this category, but these pathways all share the same internal mechanism: if a supernova of this class is formed by carbon-oxygen [

b 2], a white dwarf that accretes enough material and reaches the Chandrasekhar limit of about 1.38 solar masses (for a star that does not rotate) that it will no longer be able to balance its gravitational pull by electron degeneracy pressure and will collapse.

However, it is generally accepted in the body physics community today that this limit is unattainable under normal circumstances: as the temperature and density of the white dwarf's inner core continue to rise before the collapse occurs, the carbon combustion process will be detonated when the white dwarf reaches 1% of the limit. Within a few seconds, a significant portion of the white dwarf's material will undergo nuclear fusion, releasing enough energy (1-2×1044 joules) from it to cause a supernova explosion.

A shock wave that spreads outward is generated and can reach speeds of 5,000-20,000 km/s, which is equivalent to about 3% of the speed of light. At the same time, the luminosity of the star increases very significantly, with an absolute magnitude of -19.3 (equivalent to 5 billion times brighter than the Sun), and this luminosity hardly changes.

One of the models for studying the formation of such supernovae is a dense binary star system. The more massive star in the binary star leaves the main sequence earlier in the evolution and expands into a red giant.

As the binary's common orbit gradually shrinks, the red giant eventually ejects most of its outer material outward until it can no longer continue nuclear fusion inside. At this point, it evolved into a white dwarf composed mainly of carbon and oxygen.

The other star in the system will then evolve into a red giant, and the mass of this red giant star will be accretion by the nearby white dwarf, causing the latter to grow in mass. In orbits close enough, white dwarfs may also accretion mass from other types of companion stars, including main-sequence stars.

Another model for the formation of a type Ia supernova explosion is the merger of two white dwarfs, at which point the combined mass is likely to exceed the Chandrasekhar limit, but this is less likely to occur than the former.

Type Ia supernovae have a characteristic photometric curve, and its luminosity is a function of time after the explosion. The light radiation emitted comes from the energy released from the internal radioactive decay of nickel-56 through cobalt-56 to iron-56.

This is used to measure the distance from their host galaxy. However, recent observations have shown that the average width of their photometric curves also evolves somewhat, which means that the intrinsic luminosity of type Ia supernovae also changes, although this change is more pronounced at a larger redshift scale.

Type Ib and Ic:

The formation mechanism of these two types of supernovae is likely to be similar to the process by which the nuclear reaction fuel in massive stars is exhausted and type II supernovae are formed, but the difference is that the stars that form type Ib or Ic supernovae lose their outer layers made of hydrogen due to strong stellar winds or interactions with their companions.

Type Ib supernovae are thought to be the product of the collapse of the massive Wolf-Laye star. There is also some evidence that a small number of Type Ic supernovae are responsible for gamma-ray bursts, but there is also some suggestion that any Ib or Type Ic supernova with its outer hydrogen layer stripped of its outer layer is likely to generate a gamma-ray burst if the geometry of the explosion allows.